The invention relates to an implant for fixing neighbouring bone plates of the cranial bone, wherein the plates have an inner surface and an outer surface. The implant comprises an inner bearing element which covers a spacing gap between the bone plates, an outer bearing element which covers the spacing gap, and a connecting device which extends through the spacing gap and which, when the bearing elements approach one another, connects the bearing elements together by means of a latching or a clamping connection in such a manner that they are no longer able to be moved apart.
Implants of this type are known from the German utility model 29919090 for example. They are used in order to relocate bone plates in their original position within the cranial bone after they have been separated therefrom by means of a saw cut so that they can graft back in this position.
For this purpose, it is known to arrange plate-like bearing elements on both sides of the bone plates, which are separated from one another by a spacing gap, and to connect them together by means of a central pin or a central locking strap. Moreover, rather than utilising latching or clamping means of this type, it is also known to simply draw the two plate-like bearing elements together by means of a thread-like tensioning element and to keep them clamped against one another by means of this thread-like tensioning element.
When using pin-like connecting means, it is necessary to clamp the two bearing elements together by means of a suitable tool which engages with the connecting device, which penetrates the outer bearing element and which simultaneously moves the outer bearing element along the connecting device in the direction of the inner bearing element. Such instruments are of complicated construction and are not always easy to manipulate.
If one uses a thread-like tensioning element for connecting the two bearing elements, then it is relatively easy to manipulate it when tensioning the bearing elements. However, this method results in a connection between the bearing elements which is very flexible and may sometimes give way in an undesirable manner in certain circumstances, for example, if the thread-like tensioning elements should work loose or if they dissolve in the case where a thread of resorbable material is being used.